Effects of local estrogen therapy on recurrent urinary tract infections in young females under oral contraceptives

Background: Previous studies have demonstrated the efficacy of local application of estrogen in treating postmenopausal women with recurrent urinary tract infections (RUTI) and urinary incontinence. Younger women under oral contraceptives (OC) can suffer from similar symptoms. The aim of this pilot study was to evaluate the effectiveness of local estrogens on RUTI and the impact of local hormonal supplementation on bladder neck vascularization. Methods: 30 women (mean age 22.7 years) with a longstanding history of RUTI were included. Pre-treatment investigation included complete clinical history, urinalysis, urine culture and cystoscopy. All subjects completed a questionnaire about onset and duration of disease and quality of life before and after treatment. Local (vaginal) estrogen therapy consisted of 1 mg estriol (E3) 7 times a week for two weeks and twice a week for two additional weeks. Sonographic examination of bladder vascularization was performed before and after treatment using transperineal color Doppler ultrasound (6 MHz, Acuson Sequoia 512, Mountain View, CA, USA) with a filled bladder. After angle correction, peak systolic blood flow velocity (PSBFV) and end diastolic blood flow velocity (EDBFV) were measured in 2 bladder arteries; and the Resistive Index (RI) was calculated. Flow velocity in each vessel was measured at least four times and the mean value determined. Results: All patients completed the therapy course without severe side effects. Patients had a mean history of RUTI over 2.3 years; the mean period under OC was 3.2 years. In the follow-up period of 11 months after treatment, 24/30 patients reported no symptoms of cystitis and used no additional medication. Normal bladder epithelium in control cystoscopy after E3 therapy was seen in all patients with trigonal metaplasia and vulnerable, highly vascularized urothelium at the initial investigation. RI decreased from 0.945 to 0.705 after treatment (p < 0.001), concomitantly the mean EDBFV increased highly significantly from 0.82 cm/sec to 4.45 cm/sec after estrogen treatment (P < 0.001). Interpretation: In a majority of young patients under OC and a longstanding history of RUTI, a considerable infection-free period was achieved after local application of estrogen. Decreased RI and increased EDBFV indicate vasodilatation and less peripheral vascular resistance. Responsiveness to local E3 may correspond to improved cystoscopic findings as a consequence of increased bladder perfusion. (C) 2004 Elsevier B.V. All rights reserved.